topic How to Use tPrejob and tPostJob in Talend Studio

How to Use tPrejob and tPostJob

Anonymous — Mon, 29 Jan 2018 20:56:28 GMT

tPrejob and tPostjob are great when you need execute given tasks, before and after your job. Unlike other components, these components do not process data and cannot be configured. They always execute, even if the main job fails, making them great for tasks that need to be completed even if the job is not successful.

Some scenarios in which you might need to use tPrejob include:

loading context information
logging the start of the job
ensuring that a file exists
creating a database connection

On the other hand, you might use tPostjob to:

delete any temporary files you created within the job
log the end of a job
close any connections that you may have created

These components are added to jobs the same way any other components are, simply click and drag them from the palette or search for them by clicking on the canvas. All you need to do after that is connect them to your subjob using an “OnComponentOk” connection. Bellow, is an example of tPrejob and tPostjob being utilized.

Re: How to Use tPrejob and tPostJob

Anonymous — Tue, 30 Jan 2018 06:34:50 GMT

Hello,

Thanks for sharing it with us.

Best regards

Sabrina

Re: How to Use tPrejob and tPostJob

Anonymous — Wed, 15 Aug 2018 21:35:33 GMT

Thanks for the post/information.

Just to be absolutely clear, the screen shot shown is BEFORE the OnComponentOk connections to the subjob have been added? The subjob being the employee to tMap to tFileOutputDelimited?

Or is the screen shot the "final" product?

Re: How to Use tPrejob and tPostJob

ThWabi — Thu, 06 Sep 2018 13:14:17 GMT

Hello CygnusX1,

the screenshot shows the final job design. There is no connection from PreJob to the main subjob or from there to PostJob. The "employee" component has a green background, that means it is the start component of the main subjob (executed after PreJob and before PostJob).

Best regards,

Thomas

Re: How to Use tPrejob and tPostJob

Anonymous — Thu, 28 Feb 2019 21:34:36 GMT

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Re: How to Use tPrejob and tPostJob

Anonymous — Fri, 29 Mar 2019 16:41:02 GMT

wow! looks great, thank you for sharing!
I've found just this http://umashanthan.blogspot.com/2016/01/when-or-how-to-use-tprejob-and-tpostjob.html link and it was cool to see one more example of this. for me, as a freelance writer working on different educational projects that's really important

Re: How to Use tPrejob and tPostJob

Anonymous — Fri, 29 Mar 2019 16:42:14 GMT

Re: How to Use tPrejob and tPostJob

Anonymous — Fri, 29 Mar 2019 16:45:05 GMT

wow! looks great, thank you for sharing!
I've found just this http://umashanthan.blogspot.com/2016/01/when-or-how-to-use-tprejob-and-tpostjob.html and it was cool to see one more example of this. for me, as a freelance writer working on different educational projects that's really important

Re: How to Use tPrejob and tPostJob

michad — Mon, 08 Apr 2019 12:57:49 GMT

If you want to use these components, I think it is necessary to check the state of the prejob before starting main. And this is especially necessary in the case of a base extraction in the middle of a job that lasts one hour.

The control can be simple, something like this for example:

Re: How to Use tPrejob and tPostJob

lennelei — Tue, 25 Jun 2019 16:51:27 GMT

Hi,
Great post, however, I'm not a huge fan of using tPreJob for DB connection: if the connection fails, the job will continue unnecessarily (worse, it might even start to do something that will have to be reverted later).
tPreJob should really be used with care perfectly knowing that it won't stop the job if it fails!
The tPostJob on the other hand is really usefull.
Regards.

Re: How to Use tPrejob and tPostJob

martel — Wed, 20 Nov 2019 07:48:29 GMT

And the Advanced settings of tDie : Exit JVM immediately ? tPrejob_1 -> tPostgresqlConnection_1 --[OnSubjobError]--> tDie

Re: How to Use tPrejob and tPostJob

xrocq — Wed, 20 Nov 2019 09:57:46 GMT

Hi, i've got a problem with the Postjob execution

In my simple test case here :

What i expect : Tdie Error then Only execute the Postjob part

Try 1 => tDie advanced option set with checked "Exit the JVM immediately"

What i got = Tdie Error and no Postjob execution

Try 2 => tDie advanced option set with unchecked "Exit the JVM immediately"

What i got = Tdie Error and Main Part execution and Postjob execution

The only solution i found to have what i expect is using a empty tJava with if link on the tDie CODE:

So the tPostjob isnt working in any case ?

Re: How to Use tPrejob and tPostJob

martel — Wed, 20 Nov 2019 10:30:12 GMT

What i expect : Tdie Error then Only execute the Postjob part
??? why you dont add preJobMessagePrint in Prejob and finishing by tDie (and checked stop JVM immediately) ? more simple

Re: How to Use tPrejob and tPostJob

xrocq — Wed, 20 Nov 2019 11:03:43 GMT

@martel This is just a simple test to deal with tDie and PostJob

In fact what i really need is that tPostjob part (whatever it contains) execute in anycase

But stopping job execution in case of tDie (DB connection error, missing file...)